Pneumatic tool.



W. H. VAN SICKEL.

PNEUMATIQTOOL. i APPLICATION FILED FEB. 18, 1909.

Patented Sept. 21, 1909.

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UNITED sTATEs i' A'i Ei\rr oEEicE.

WILBER H. VAN SICKEL, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR '110`THOS. H. DALLETT C0., A CORPORATION OF NEW JERSEY.

PNEUMATIC Toor..

Application filed February 18, 1909.

To all whom it 'may concern:

Beit known that I,VVILBER H. VAN SICKEL, a citizen of the United States,residing at Philadelphia, county of Philadelphia, and State ofPennsylvania, have invented a new and .useful Improvement in PneumaticTools, of which the following is a full, clear, and exact description,reference being had to the accompanying drawings, which form a part oi'this specication.

My invention relates particularly to certain improvements in the valvemechanism ot' pneumatic tools and by which the operation of the tool ismade more rapid and certain, and also to cushioning the piston in itsdownward stroke independent of the shift of the valve.

Speaking generally: I employ a hollow valve in the valve chamber, theinterior of which, through its open end, is in constant communicationwith the air supply. In the upper portion ot' the valve chamber is alateral passage through the valve chamber which, in one position of thevalve, is covered by the valve skirt. Vhen the valve moves to its otherposition, this passage is uncovered and receives air from the airsupply. This passage terminates in a longitudinal passage leading to theupper portion of the piston chamber. In order to insure, with certainty,a full amount of air to act on the upper portion of the piston, Iprovide openings through the valve, which in the position of the valve,when the first mentioned lateral passage is uncovered from the valveskirt, communicate with a lateral passage through the valve chamber,opening into the longitudinal passage leading to the upper portion ofthe piston chamber. In the other position ot the valve these openingsthrough the valve communicate with a lateral pas sage through the valvechamber communicating with a longitudinal passage to the lower portionof the piston chamber. The action of the air upon the piston to drive itdown being most important, my new valve mechanism enables the air to actquickly upon the upperportion of the piston, and sufficient air isinsured to give the desired power. All of this I obtain with simplicityot' construction.

I will now describe the embodiment of my invention illustrated in theaccompanying drawing and then point out the invention in l the claims.

Specification of Letters Patent.

rammed sept. 21, 1909.

Serial No. 478,710.

In the drawings: Figure 1 is a sectional view of a pneumatic toolembodying my invention with the valve and piston in one position. Fig. 2is a similar view with the parts in the other position.

a is the valve chamber, o the valve therein. This valve is hollow, vtheinterior of which valve is in constant communication with the pressuresupply through its open end. The lower portion or head ot' this valve isprovided with the flanges c so that the exterior of the valve at thispoint is ot' greater area than the interior portion at that point andthe area of the valve skirt d.

c is a longitudinal passage extending from the upper end of the pistonchamber /L to a point near the top of the valve chamber where itcommunicates with a lateral passage f, which lateral passage f is, inthe position of the valve shown in Fig. 2, covered by the valve skirt d,and in the position shown in Fig. l it is not covered by the valveskirt.

g is a longitudinal passage extending from the lower portion of thepiston chamber 7L to the lateral passage z' extending through the wallof the valve chamber.

j is a lateral passage extending through the valve chamber, andcommunicating with the piston passage e.

73 are ports or openings through t-he valve. In the position shown inFig. l, these openings register with the passage j, and when in theposition shown in Fig. 2, these open` ings 7c register with the passagez'.

Z is a chamber formed in the valve chamber and in constant communicationwith the exhaust passage m.

a is a longitudinal passage leading from an intermediate point of thepiston chamber to the pressure supply.

0 is an exhaust passage. n

p is a passage leading from the valvechamber below the valve head andopening into the piston chamber at two points, one point opposite thepoint of openingof pas- 100 sage a, the other point opposite the exhausto.

rPhe operation of the tool is as follows: In the position shown in Fig.1, the valve chamber below the valve is in communication with 105 theexhaust through passage p and exhaust o. The pressure supply in theinterior of the valve holds the valve in the position shown. Thepressure below the piston g is exhausted through exhaust o. The pressureenters lat- 110 soA eral passage f and passes by longitudinal passage eto the top of the piston, forcing the piston down. A supplemental supplyof air is delivered on the top of the piston through the ports 7c,lateral passages j, and longitudinal passage e. When the grooved portion1" of the piston reaches the opening of passage n, the solid portion hascovered the opening t of passage p and exhaust 0. Pressure then passesto passage p through opening w and, by reason of the greater area actedon, the valve is moved to the position shown in F ig'. 2. In thisposition the skirt Z of the valve covers the passage f', and the portsor openings 7c no longer register with the passages y', and pressuredoes not pass through the passage e. The passage e however, is incommunication with chamber Z and the pressure above the piston exhausts.The ports 7a, in this position of the valve, are in communication withthe passage z', and pressure is admitted below the piston and it islifted. This continues until the grooved portion of the piston passesbeyond opening of passage nl and the solid portion of piston has passedbeyond the exhaust 0, and covered opening w, at which time the pressurebelow the valve is relieved, and the constant pressure in the interiorof the valve shifts it to the position shown in Fig. l. I also usecertain means to cushion the piston in its downward movement. Theadmission of such cushioning being controlled solely by the movement ofthe piston. By this arrangement I am enabled to admit pressure below thepiston independent of the shift of the valve, and thus allow pressure toact on the top of the piston for a greater time than is the case if thepressure admission below the piston is dependent upon the shift of thevalve. For this purpose I employ the longitudinal passage y, having theport z opening into the piston chamber at a point at or near its lowerend, and also having a port 10 opening where, when the piston groove runcovers the opening or passage n, the piston groove will register withthe port 10 and pressure will enter passage y and pass through port s toa point at or near the lower end of the piston chamber. By thisarrangement, the admission of the air to cushion is in no way dependentupon the shift of the valve. Therefore, the piston, in its down stroke,can be held longer under the action of live air and be provided withcushioning, than if the admission of the air to cushion were dependentupon the shift of -the valve. Further, while initially the bushing 2 andstriking portion of the piston make a snug lit, still under wear of usethere is likely to be leakage at this point, which leakage iscompensated for by the increased amount of live air admitted, in myconstruction, to the lower portion of the piston chamber.

Having now fully described my invention, what I claim and desire toprotect by Letters Patent is:

l. In a pneumatic tool, a piston chamber, a piston therein, there beinga longitudinal passage leading from the upper portion of piston chamber,a valve chamber, a hollow valve therein, said valve having a iangeintermediate of its length limiting the movement of said valve in onedirection, the interior of said valve communicating at its open end withthe pressure supply, a lateral passage at one end of said valve chamberpassing through the wall of said chamber and communicating with thelongitudinal passage, said valve having a skirt which in one position ofthe valve covers said lateral passage, and in the other position passesbeyond said passage, said valve having openings therethrough, therebeing a passage leading from the longitudinal passage, said valveopenings registering with said lastmentioned passage when the lateralpassage is uncovered by the skirt.

2. In a pneumatic tool, a piston chamber, a piston therein, there beinga longitudinal passage leading from the upper portion of the pistonchamber, a valve chamber, a hollow valve therein having a lower enlargedhead, the interior of the valve communicating at its open end with thepressure supply, a lateral passage at the upper end of said valvechamber passing through the wall of said chamber and communicating withthe longitudinal passage, said valve having a skirt which in the upperposition oi. 'said valve covers said lateral passage, and in the lowerposition passes beyond said passage, said valve having openingstherethrough, there being a passage leading from the longitudinalpassage, said valve openings registering with said last mentionedpassage in one position of the valve.

3. In a pneumatic tool, a piston chamber, a piston therein, there beinga longitudinal passage leading from the upper portion of piston chamber,a valve chamber in line with said piston chamber, a hollow valvetherein, the interior of which communicates at its open end with thepressure supply, a lateral passage at one end of said valve chamber'passing through the wall of said chamber and communicating with thelongitudinal passage, said valve having a skirt, which in one positionof the valve covers said lateral passage, and in the other positionpasses beyond said passage, said valve having openings therethrough,there being a passage leading from the longitudinal passage, said valveopenings registering with said last mentioned passage in one position ofthe valve.

4. In a pneumatic tool, a piston chamber, a piston therein, there beinga longitudinal passage leading from the upper portion of piston chamber,a valve chamber, a hollow valve therein, the interior of whichcommunicates at its open end with the pressure supply, a lateral passageat one end of said valve chamber passing through the wall of saidchamber and communicating with the longitudinal passage, said valvehaving a skirt which in one position of the valve covers said lateralpassage, and in the other position passes beyond said passage, saidvalve having openings therethrough, there being a passage leading fromthe longitudinal passage, said valve openings registering with said lastmentioned passage in one position of the valve, there being a passageleading from the lower portion of the piston chamber, said passagecommunicating with the valve chamber, said valve openings registeringwith said communication in the other position of the valve.

5. In a pneumatic tool, a piston chamber, a piston therein, there beinga longitudinal passage leading from the upper portion of the pistonchamber, a valve chamber, a hollow valve therein having a lower enlargedhead, the interior of the valve communicating at its open end with thepressure supply, a lateralpassage at the upper end of said valve chamberpassing through the wall of said chamber and communicating with thelongitudinal passage, said valve having a skirt which in the upperposition of said valve covers said lateral passage, and in the lowerposition passes beyond said passage, said valve having openingstherethrough, there being a passage leading from the longitudinalpassage, said valve openings registering with said last mentionedpassage in one position of the valve, there being a passageleading fromthe lower portion of the piston chamber, said passage communicating withthe valve chamber, said valve openings registering with saidcommunication in the upper position of the valve.

G. In a pneumatic tool, a piston chamber, a piston therein, there beinga longitudinal passage leading from the upper portion of piston chamber,a valve chamber in line with said piston chamber, a hollow valvetherein, the interior of which communicates at its open end with thepressure supply, a lateral :passage at one end of said valve chamberpassing through the wall of said chamber and communicating with thelongitudinal passage, said valve having a skirt, which in one positionof the valve covers said lateral passage, and in the other positionpasses beyond said passage, said valve having openings therethrough,there being a passage leading from the piston passage, said valveopenings registering with said last mentioned passage in one position ofthe valve,

there being a passage leading from the lower end of the piston chamber,said passage communieating with the valve chamber, said valve openingsregistering with said communication in the other position of the valve.

7. In a pneumatic tool, the combination with the piston chamber andpiston having a cut-away portion therein, the valve chamber and valvetherein, of a passage in constant communication with the air supply, apassage from the piston chamber to the valve chamber for shifting thevalve in the downward movement of the piston, and a passage admittingair below the piston in the shift of said valve, of a second passageleading to the lower portion of the piston chamber, the cut-away portionof the piston, in the downward movement of the piston, independent ofthe shift of the valve, connecting the constant air passage and the saidsecond passage leading to the lower portion of the cylinder.

8. In a pneumatic tool, the combination with the piston chamber andpiston having a cut-away portion therein, the valve chamber and valvetherein, of a passage in constant communication with the air supply, apassage from the piston chamber to the valve chamber for shifting thevalve in the downward movement of the piston, and a passage admittingair below the piston in the shift of said valve, of a second passageleading to the lower portion of the piston chamber, the cut-away portionof the piston, in the downward movement of the piston, connecting theconstant air passage with the passage to the valve chamber to shift thevalve, and with the said second passage to the lower portion of thecylinder. v

9. In a pneumatic tool, the combination with the piston chamber andpiston having a cut-away portion therein, the valve chamber and valvetherein, of a passage in constant communication with the airfsupply, apassage from the piston chamber to the valve chamber for shifting thevalve in the downward movement of the piston to admit air below thepiston, of a passage leading to the lower portion of the piston chamber,the cut-away portion of the piston, in the downward movement of thepiston, first connecting the constant air passage with the passage tothe valve chamber and then the constant air passage with the passage tothe lower portion of the piston chamber.

In testimony of which invention, I have hereunto set my hand, atPhiladelphia, on this 16th day of February, 1909.

VILBER H. VAN SICKEL. lVitnesses M. M. HAMILTON, E. E. WALL.

